The search for improved methods for detecting and identifying characteristic markers of a wide variety of diseases, including destructive connective tissue diseases such as periodontal disease and rheumatoid arthritis, is an ongoing one.
Release of specific tissue constituents into biological fluids generally occurs due to normal tissue turnover. In disease, excessive release may occur such that tissue constituents may serve as markers of active disease. Examples of characteristic markers which may be detected by this method include glycosaminoglycans, specific proteins, etc. The glycosaminoglycans of interest may include hyaluronic acid, a variety of chondroitin sulfates, etc.
Glycosaminoglycans (GAG) (hexuronate-containing heteropolysaccharides) are polyanionic constituents of proteoglycans, which are characteristic components of connective tissues in the body. The use of GAG as a cancer-specific marker is discussed in U.S. Pat. No. 4,468,465. In this patent, a cellulose acetate membrane electrophoresis method was utilized to study the GAG. By using a combination of an electric field and appropriate electrolytes, GAG were separated according to their charge densities or backbone structures.
It has also been postulated that specific GAG in human gingival crevicular fluid are characteristic markers of periodontal disease, the destruction of tooth-supporting tissues. Periodontal disease activity has been correlated with the presence of GAG using electrophoresis, (K. S. Last, J. B. Stanbury and G. Embery, "Glycosaminoglycans in Human Gingival Crevicular Fluid as Indicators of Active Periodontal Disease", Archives of Oral Biology, Vol. 30, No. 3, pp. 275-281 (1985)). The method disclosed by Last, et al. included collecting gingival crevicular fluid by capillary action into 2 or 5 .mu.l pipettes, then applying the samples to sheets of cellulose acetate, which were then subjected to electrophoresis. After electrophoresis the cellulose acetate sheets were stained using Alcian blue. A similar method of characterizing the GAG by staining and electrophoresis was disclosed in L. Hronowski and T. Anastassiades, "Characterization of Glycosaminoglycan-Alcian Blue Complexes by Elution from Cellulose Acetate Utilizing Different MgCl.sub.2 Concentrations", Analytical Biochemistry, Vol. 107, pp. 393-405 (1980).
The procedures referenced above require specialized equipment, a certain degree of expertise and a substantial wait before results are available.
Therefore, there still exists a need for a simple, relatively fast method for detecting and identifying characteristic markers of diseases including destructive connective tissue diseases such as periodontal disease and rheumatoid arthritis.